syzbot

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BUG: KASAN: slab-use-after-free in xfrm_state_find+0x35b8/0x4510 net/xfrm/xfrm_state.c:1357
Read of size 1 at addr ffff8880531716f8 by task syz.1.5497/27158

CPU: 1 PID: 27158 Comm: syz.1.5497 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xac/0x220 mm/kasan/report.c:468
 kasan_report+0x117/0x150 mm/kasan/report.c:581
 xfrm_state_find+0x35b8/0x4510 net/xfrm/xfrm_state.c:1357
 xfrm_tmpl_resolve_one net/xfrm/xfrm_policy.c:2502 [inline]
 xfrm_tmpl_resolve net/xfrm/xfrm_policy.c:2547 [inline]
 xfrm_resolve_and_create_bundle+0x727/0x2c20 net/xfrm/xfrm_policy.c:2841
 xfrm_bundle_lookup net/xfrm/xfrm_policy.c:3076 [inline]
 xfrm_lookup_with_ifid+0x556/0x19c0 net/xfrm/xfrm_policy.c:3207
 xfrm_lookup net/xfrm/xfrm_policy.c:3304 [inline]
 xfrm_lookup_route+0x3c/0x1b0 net/xfrm/xfrm_policy.c:3315
 sctp_v6_get_dst+0x6b0/0x1b90 net/sctp/ipv6.c:327
 sctp_transport_route+0x10b/0x2c0 net/sctp/transport.c:457
 sctp_assoc_add_peer+0x650/0x13a0 net/sctp/associola.c:663
 sctp_connect_new_asoc+0x304/0x690 net/sctp/socket.c:1099
 sctp_sendmsg_new_asoc net/sctp/socket.c:1693 [inline]
 sctp_sendmsg+0x155c/0x27e0 net/sctp/socket.c:2004
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x5bf/0x950 net/socket.c:2595
 ___sys_sendmsg+0x220/0x290 net/socket.c:2649
 __sys_sendmmsg+0x275/0x4a0 net/socket.c:2735
 __do_sys_sendmmsg net/socket.c:2764 [inline]
 __se_sys_sendmmsg net/socket.c:2761 [inline]
 __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2761
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f3b7278ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3b709d5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f3b729c6180 RCX: 00007f3b7278ebe9
RDX: 0000000000000001 RSI: 0000200000000a80 RDI: 0000000000000004
RBP: 00007f3b72811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000004c040 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3b729c6218 R14: 00007f3b729c6180 R15: 00007ffc69658998
 </TASK>

Allocated by task 26817:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 __do_kmalloc_node mm/slab_common.c:1007 [inline]
 __kmalloc+0xb4/0x240 mm/slab_common.c:1020
 kmalloc_array include/linux/slab.h:637 [inline]
 kcalloc include/linux/slab.h:668 [inline]
 iter_file_splice_write+0x18a/0xc50 fs/splice.c:676
 do_splice_from fs/splice.c:933 [inline]
 direct_splice_actor+0xe8/0x130 fs/splice.c:1142
 splice_direct_to_actor+0x2f0/0x870 fs/splice.c:1088
 do_splice_direct+0x1b7/0x2c0 fs/splice.c:1194
 do_sendfile+0x5dc/0xf70 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1316 [inline]
 __se_sys_sendfile64+0xda/0x190 fs/read_write.c:1308
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Freed by task 26817:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1806 [inline]
 slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1832
 slab_free mm/slub.c:3816 [inline]
 __kmem_cache_free+0xba/0x1f0 mm/slub.c:3829
 iter_file_splice_write+0xab0/0xc50 fs/splice.c:764
 do_splice_from fs/splice.c:933 [inline]
 direct_splice_actor+0xe8/0x130 fs/splice.c:1142
 splice_direct_to_actor+0x2f0/0x870 fs/splice.c:1088
 do_splice_direct+0x1b7/0x2c0 fs/splice.c:1194
 do_sendfile+0x5dc/0xf70 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1316 [inline]
 __se_sys_sendfile64+0xda/0x190 fs/read_write.c:1308
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff888053171600
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 248 bytes inside of
 freed 256-byte region [ffff888053171600, ffff888053171700)

The buggy address belongs to the physical page:
page:ffffea00014c5c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x53170
head:ffffea00014c5c00 order:1 entire_mapcount:0 nr_pages_mapped:0 pincount:0
ksm flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888017841b40 ffffea0001674500 dead000000000003
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 20113, tgid 20105 (syz.0.3668), ts 1693275460674, free_ts 1691216727238
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554
 prep_new_page mm/page_alloc.c:1561 [inline]
 get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
 alloc_slab_page+0x5d/0x170 mm/slub.c:1876
 allocate_slab mm/slub.c:2023 [inline]
 new_slab+0x87/0x2e0 mm/slub.c:2076
 ___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230
 __slab_alloc mm/slub.c:3329 [inline]
 __slab_alloc_node mm/slub.c:3382 [inline]
 slab_alloc_node mm/slub.c:3475 [inline]
 __kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3524
 __do_kmalloc_node mm/slab_common.c:1006 [inline]
 __kmalloc+0xa4/0x240 mm/slab_common.c:1020
 kmalloc_array include/linux/slab.h:637 [inline]
 kcalloc include/linux/slab.h:668 [inline]
 iter_file_splice_write+0x18a/0xc50 fs/splice.c:676
 do_splice_from fs/splice.c:933 [inline]
 direct_splice_actor+0xe8/0x130 fs/splice.c:1142
 splice_direct_to_actor+0x2f0/0x870 fs/splice.c:1088
 do_splice_direct+0x1b7/0x2c0 fs/splice.c:1194
 do_sendfile+0x5dc/0xf70 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1316 [inline]
 __se_sys_sendfile64+0xda/0x190 fs/read_write.c:1308
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1154 [inline]
 free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336
 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429
 discard_slab mm/slub.c:2122 [inline]
 __unfreeze_partials+0x1cf/0x210 mm/slub.c:2662
 put_cpu_partial+0x17c/0x250 mm/slub.c:2738
 __slab_free+0x31d/0x410 mm/slub.c:3686
 qlink_free mm/kasan/quarantine.c:166 [inline]
 qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185
 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
 slab_alloc_node mm/slub.c:3485 [inline]
 slab_alloc mm/slub.c:3493 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3500 [inline]
 kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3509
 vm_area_dup+0x27/0x270 kernel/fork.c:501
 dup_mmap kernel/fork.c:711 [inline]
 dup_mm kernel/fork.c:1692 [inline]
 copy_mm+0xc08/0x1c20 kernel/fork.c:1741
 copy_process+0x16d3/0x3d70 kernel/fork.c:2506
 kernel_clone+0x21b/0x840 kernel/fork.c:2914
 __do_sys_clone kernel/fork.c:3057 [inline]
 __se_sys_clone kernel/fork.c:3041 [inline]
 __x64_sys_clone+0x18c/0x1e0 kernel/fork.c:3041
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81

Memory state around the buggy address:
 ffff888053171580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888053171600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888053171680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                                ^
 ffff888053171700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888053171780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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